The present invention relates to a disk centering system. More particularly, the present invention relates to a technical field in which a disk form recording medium is centered by a plurality of disk centering members for pressing the outer circumferential edge of the disk form recording medium, whereby the disk form recording medium can be centered irrespectively of the size thereof and can be handled with enhanced ease.
Among disk drives capable of recording and/or reproduction of information signals onto and/or from a disk form recording medium such as an optical disk and a magneto-optical disk, there are those which are provided with a disk centering system for centering the disk form recording medium and which can perform recording and/or reproduction of information signals onto and/or from both the disk form recording media about 8 cm in diameter and the disk form recording media about 12 cm in diameter.
The disk centering systems provided in such disk drives include the following types.
A first type is a tray-type disk centering system including a disk tray which is supported on an outer casing of the disk drive so that it can be drawn out.
In the tray-type disk centering system, the disk tray is concentrically provided with a recessed portion for mounting a disk form recording medium about 8 cm in diameter and a recessed portion for mounting a disk form recording medium about 12 cm in diameter. When the disk tray with the disk form recording medium about 8 cm in diameter or the disk form recording medium about 12 cm in diameter being mounted in the relevant recessed portion is drawn into the inside of the outer casing and moved to a predetermined centering position, the disk form recording medium is mounted onto a disk table at the centering position. The recessed portions for mounting are formed to be slightly larger than the diameters of the respective disk form recording media.
A second type is a slot-in type disk centering system in which a disk form recording medium is inserted through a disk insertion port formed in the outer casing of the disk drive (see, for example, Japanese Patent Laid-open No. Hei 10-255366).
In the slot-in type disk centering system, when a disk form recording medium is inserted through the disk insertion port and fed into the inside of the outer casing by feeding rollers, the disk form recording medium is centered by a disk centering mechanism, and the disk form recording medium thus centered is mounted onto a disk table.
However, the conventional disk centering systems involve the following problems.
In the tray-type disk centering system, it is necessary to provide the disk tray with the recessed portions corresponding respectively to the sizes of the disk form recording media. On the other hand, there is a limitation as to the number of the recessed portions which can be formed in the disk tray. Therefore, the sizes (diameters) of the disk form recording media which can be mounted onto the disk table are limited.
In the slot-in type disk centering system, the sizes of the disk form recording media which can be used with the system are predetermined, and the size of the disk form recording medium drawn into the inside of the outer casing is detected mechanically or electrically, before the disk form recording medium is mounted onto the disk table. Thus, again, the kinds (sizes) of the disk form recording media which can be mounted onto the disk table are limited.
However, in view of the enhancement of the recording density on disk form recording media and the progress of variety of disk form recording media in the future, it is highly possible that disk form recording media with various diameter values will be commercialized, in addition to the disk form recording media about 8 cm or about 12 cm in diameter. It is impossible to cope with the disk form recording media having various diameter values by use of the conventional disk centering systems.
In addition, in the tray-type disk centering system, the difference in size between the recessed portion and the corresponding disk form recording medium is slight. Therefore, it is necessary to mount the disk form recording medium into the recessed portion with highly accurate alignment, which leads to a troublesome handling of the disk form recording medium.
Further, in the slot-in type disk centering system, also, it is necessary to insert each disk form recording medium into the disk insertion port with no positional misalignment therebetween, which leads to a troublesome handling of the disk form recording medium. Besides, in the slot-in type disk centering system, both sides of the disk form recording medium are clamped between a pair of rollers when the disk form recording medium is fed into the inside of the disk drive, so that the disk form recording medium may be scratched or damaged due to the contact thereof with the rollers.
On the other hand, among the disk drives, there are those in which a disk table is provided with engagement claws capable of elastic deformation in radial directions, and the inner circumferential edge of the disk form recording medium is pressed against the engagement claws to elastically deform the engagement claws at the time of mounting the disk form recording medium onto the disk table. In such a disk drive, since the inner circumferential edge of the disk form recording medium is pressed against the engagement claws, there is the problem that the inner circumferential edge of the disk form recording medium may be damaged or the disk form recording medium may be deformed.